Air filter assembly capable of top and bottom loading

ABSTRACT

A baghouse filter having a filter media and an end cap is provided. The filter media has a longitudinal axis, and the end cap has an outer peripheral side wall. The side wall has first and second edges. A first recessed channel extends between the first and second edges of the side wall, and a second recessed channel extends from the first channel. The first and second channels define a connection area at which the filter connects to the tubesheet at an opening in the tubesheet. Also, a method is provided for installing a filter on a tubesheet having first and second sides separating plenums of a baghouse. The method includes providing a filter having structure for attaching to a tubesheet opening from either side, selecting the side to install the filter and installing the filter on the selected side.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119(e), priority benefits are claimed herein fromco-pending provisional application Serial No. 60/216,717, filed on Jul.7, 2000, entitled “Air Filter Assembly Capable of Top and BottomLoading”.

BACKGROUND OF THE INVENTION

The present invention generally relates to filters within a baghouse andmore particularly to an air filter capable of being mounted from eitherthe top or the bottom of the tubesheet.

Filter assemblies are commonly used for removing particulates andaerosols from the air in industrial environments. One type of commonfilter assembly is an industrial baghouse. Baghouses typically includetwo large chambers, or plenums, that are divided by a tube sheet. Thefilter cartridges, preferably containing fabric filtration elements, aresecured to the tube sheet at one end to suspend the cartridge in thelower plenum. Fabric filter media having longitudinal pleatings areparticularly effective for removing particulates. One such air filtercartridge is disclosed in U.S. Pat. No. 5,632,791 to Reinout G. Oussorenand Jack T. Clements, herein incorporated by reference in its entirety.

Air containing unwanted particulates is forced into the first plenum bya forced air means such as a fan. The air passes from the first plenumto the second plenum via the air filter cartridges held by the tube (orpan) sheet. The particulates are retained on the outer surface of thefabric filter element of the cartridge filter, and the clean air isdirected into the second plenum and exits the baghouse through anexhaust passageway.

To suspend the cartridges from the tube sheet, the cartridges are eitherloaded from the upper or lower plenum. Specifically, to load thecartridges from the upper plenum or “top load” the cartridges, thecartridge is slidingly received within the appropriate opening and thetop cap of the cartridge is frictionally secured to the tubesheet at oneof the openings. To load from the lower plenum or “bottom load” thecartridge, the cartridge is raised into proximity with the tubesheet andthe top cap of the cartridge is attached to the tubesheet at one of theopenings. The decision to top or bottom load the cartridge is oftendictated by the accessibility and size of the plenums. If the upperplenum is spacious, a worker may move within the upper plenum to loadthe cartridges by top loading. Conversely, if the lower plenum is moreaccessible and provides the necessary space, the cartridges aretypically bottom loaded.

However, in the past, air filter cartridges are designed for either topor bottom loading, but not both. Accordingly, the operator of thebaghouse must have the appropriate type of either bottom load or topload cartridges for the particular baghouse. In industrial environmentshaving both top and bottom load baghouses, an inventory of filtercartridges must be maintained for each baghouse. Accordingly, there is aneed for an air filter cartridge capable of top and bottom loadingwithin a baghouse.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide an air filtercartridge capable of top and bottom loading within a filter assembly. Inaccordance with the foregoing and other objects evident from thefollowing description of a preferred embodiment of the invention, abaghouse filter having a filter media and an end cap is provided. Thefilter media has a longitudinal axis, and the end cap has an outerperipheral side wall. The side wall has first and second edges. A firstrecessed channel extends between the first and second edges of the sidewall, and a second recessed channel extends from the first channel. Thefirst and second channels define a connection area at which the filterconnects to the tubesheet at an opening in the tubesheet.

In accordance with another aspect of the invention, the filter has afilter media and an end cap. The end cap has first and second connectorportions. The first connector portion mates with the tubesheet at atubesheet opening when the filter is installed from the bottom plenum.The second connector portion mates with the tubesheet at a tubesheetopening when the filter is installed from the bottom plenum.

In yet another aspect of the invention, a tubesheet is provided having aplanar sheet, a number of openings in the sheet and a number of collars.Each collar is positioned about an opening in the sheet and extendsnormally from the sheet. Each collar has an inner face directed towardthe center of the opening about which the collar is positioned. Thecollars include a number of elements extending radially from the innerface toward the center of the opening.

In still another aspect of the invention, a method is provided forinstalling a filter on a tubesheet having first and second sidesseparating plenums of a baghouse. The method includes providing a filterhaving structure for attaching to a tubesheet opening from either side,selecting the side to install the filter and installing the filter onthe selected side.

In another aspect of the invention, a tool for securing a filtercartridge to or from a tubesheet is provided. The tool has an elongatedshaft, a handle, a disc and a rod. The handle is positioned at a firstend of the shaft. The disc is disposed on the other end of the shaft andis aligned normally with respect to the shaft. The rod is coupled withthe disc and has opposing ends extending beyond the periphery of thedisc.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The following description of the drawings, in which like referencenumerals are employed to indicate like parts in various views:

FIG. 1 is a schematic view of the interior of a filter assemblydemonstrating top loading of an air filter cartridge;

FIG. 2 is a schematic view of the interior of a filter assemblydemonstrating bottom loading of an air filter cartridge;

FIG. 3 is an exploded perspective view of an adaptor plate and tubesheet according to the present invention;

FIG. 4 is a fragmentary, exploded elevational view of an air filtercartridge of the present invention being bottom loaded with the filterassembly;

FIG. 5 is a fragmentary, elevational view of the air filter cartridge ofFIG. 4 being top loaded within the filter assembly;

FIG. 6 is a fragmentary, elevational view of the filter cartridge lockedonto the adaptor plate of FIG. 3;

FIG. 7 is an enlarged fragmentary sectional view of the air filterassembly taken along line 7—7 of FIG. 6;

FIG. 8 is a top plan view of the air filter cartridge taken along lines8—8 of FIG. 4;

FIG. 9 is a bottom plan view of the air filter cartridge taken alonglines 9—9 of FIG. 2;

FIG. 10 is a perspective view of a tool used in accordance with thepresent invention;

FIG. 11 is an exploded elevational view of the air filter cartridge ofFIGS. 5 and 6 and an alternative connection device with parts brokenaway for ease of illustration;

FIG. 12 is an enlarged sectional view of the filter cartridge lockedonto the alternative connection device of FIG. 11;

FIG. 13 is an enlarged sectional view of the air filter cartridge lockedonto a second alternative connection device;

FIG. 14 is a fragmentary top plan view of a tube sheet of the air filterassembly having a plurality of notches to engage the air filtercartridge;

FIG. 15 is an exploded partial elevational view of an air filtercartridge of a second embodiment of the present invention, wherein thefilter cartridge is shown as being bottom loaded on the tube sheet ofFIG. 14;

FIG. 16 is a fragmentary elevational view demonstrating the air filtercartridge of the second embodiment in the bottom-loaded, lockedposition;

FIG. 17 is a fragmentary side elevational view demonstrating the airfilter cartridge of the second embodiment in the top loaded, lockedposition;

FIG. 18 is a plan view taken along lines 18—18 of FIG. 16;

FIG. 19 illustrates, by plan view, a modification to the secondembodiment of the air filter cartridge used in conjunction with the tubesheet of FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

With initial reference to FIG. 1, a baghouse, utilizing filtercartridges made in accordance with the present invention is designatedgenerally by the reference numeral 10. Baghouse 10 is defined by anenclosed housing 12 made from a suitable material such as sheet metal.Gas flows through the baghouse 10 from an inlet 14. Gas is filtered by aplurality of filter cartridges 16 and exits the baghouse 10 through anoutlet 18. The filter cartridges 16 are secured to a tubesheet 20, thusdefining a lower plenum 22 and an upper plenum 24. Specifically, eachair filter cartridge 16 is secured within the tubesheet 20 at one of aplurality of openings 26 formed within the tube sheet 20.

The housing 12 of the baghouse 10 includes a number of sides 28 and aroof 30. As shown in FIG. 1, some baghouses have larger or moreaccessible upper plenums 24 allowing for the filter cartridges 16 to beloaded from the top of the tubesheet 20 and secured within theappropriate opening 26. For instance, the height of the upper plenum 24may allow for a worker to move within the plenum 24, or the roof 30 maybe removable to allow access into the baghouse 10 for top loading. Asshown in FIG. 2, in some baghouses, the upper plenum 24 does not have asufficient height to allow for top loading and thus the filtercartridges 16 are loaded from the lower plenum 22.

With reference to FIG. 3, an opening 26 of tubesheet 20 is illustrated.In some prior art connection devices, a number of bolts 32 are placedaround the periphery of the circular opening 26. Typically, the bolts 32are angularly equidistant from one another. For instance as shown inFIG. 3, each bolt is offset by 90° from the next adjacent bolt. Anotherconventional design consists of three bolts offset one from another by120°. In accordance with the principles of the present invention, anadaptor plate 34 is placed over the existing bolts 32. Annular adaptorplate 34 has a first set of apertures 36 and a second set of apertures38. The first set of apertures 36 are spaced 90° one from another tocorrespond with the bolts 32 on the tubesheet 20. The second set ofapertures 38 are spaced 120° one from another to correspond with atubesheet having three (rather than four) bolts. Of course, the boltsand apertures may be spaced in an asymmetrical pattern about the endcap.

The adaptor plate 34 further comprises a number of L-brackets 40 spacedaround the top surface of adaptor plate 34. In the preferred embodiment,three L-brackets 40 are placed equally around the adaptor plate 34. Boththe adaptor plate 34 and L-brackets 40 are preferably made from asuitable material such as sheet metal. Each L-bracket 40 has a lowerportion 42 secured to the adaptor plate 34 and an upstanding portion 44extending normally from the surface 43 of adaptor plate 34. Eachupstanding portion 44 has an inner face 45 that is flush with theperiphery of the inner peripheral edge 47 to define a diameter D1 of theadaptor plate 34. A threaded aperture 46 is located within theupstanding portion 44 of each L-bracket 40. Bolts 48 having generallyround heads 49 are threaded within each aperture 46 and extend radiallyinwardly toward the center of the adaptor plate 34. With reference toFIGS. 3 and 4, the adaptor plate 34 is placed on the tubesheet 20 sothat the bolts 32 are received within the first set of apertures 38.When the adaptor plate 34 is in contact with tubesheet 20, nuts 50 aresecure on bolts 32 and the adaptor plate 34 is held against thetubesheet 20.

With reference to FIGS. 1 and 2, the filter cartridges 16 include afirst (top) end cap 52, a second (bottom) end cap 54 and a tubularfilter media 56 disposed therebetween. As air is cleaned, it passesthrough the tubular filter media 56 and moves upwardly through a channeldefined by the filter media 56 and into the upper plenum 24. Withreference to FIG. 4, the top end cap 52 is formed about the filter media56 as would be understand by one of ordinary skill in the art. Withreference to FIG. 7, the top end cap 52 is typically formed from apotting material 55. The potting material 55 extends about the upperedge of tubular filter media 56 and a screen member 57 as known to thoseof ordinary skill in the art.

With reference to FIGS. 4 and 8, top end cap 52 is generally annular andhas an outer diameter D2 that is slightly smaller than the diameter ofthe openings 26 of the tubesheet 20 and the diameter D1 of the openingdefined by adaptor plate 34. The inner diameter D3 (FIG. 8) of the topend cap 52 is generally equal in size to the diameter of the air flowchannel defined by tubular filter media 56 so that the top end cap 52does not obstruct the flow therethrough.

As best shown in FIG. 4, in the peripheral sidewall 51 of top end cap52, a plurality of connection areas 58 are defined between the upperedge 60 and lower edge 61 of the top end cap 52. In the preferredembodiment, each of the three connection areas 58 has a longitudinalchannel 62 and a locking channel 64. The longitudinal channel 62 runsparallel to the longitudinal axis of the tubular filter media 56 and hasa uniform depth within the top end cap 52. The locking channel 64extends generally normal to the longitudinal channel 62 and has the samedepth as the longitudinal channel. The sidewalls 65 of the lockingchannel 64 are tapered inwardly and terminate at the mouth 67 of alocking area 68. The height H of the locking area is preferably greaterthan the smallest distance (namely, that distance at mouth 67) betweenthe sidewalls of the tapered locking channel 64.

With reference to FIGS. 7 and 8, the top end cap 52 defines an annularledge 70 which extends inwardly from the sidewall 51 about the interiorof the potting material 55 proximate the collar 53. The annular ledge 70extends completely about the top end cap 52, and a groove 72 is disposedcompletely around the ledge 70. A pair of opposing notches 76 and 78 aredefined by a first pair of upstanding members 80 and a second pair ofupstanding members 82, respectively. The notches 76 and 78 are alignedlinearly with one another.

As best shown in FIG. 1, the filter cartridge 16 of the presentinvention is capable of being top loaded from the upper plenum 24 of thebaghouse 10. With specific reference to FIG. 5, the tubular filter media56 is slidingly received within the opening defined by the innerperipheral edge 47 of the adaptor plate 34 and one of the openings 26 oftubesheet 20. An annular gasket 79 (or engaging surface) is locatedaround top end cap 52 at the area of the top end cap 52 contactingtubesheet 20. The bolts 48 of adaptor plate 34 are received within thelongitudinal channels 62 of each of the connection areas 58 of top endcap 52. When the filter cartridge 16 is lowered to the depth at whichthe bolts 48 are proximate the mouth portions 66 of locking channels 64,the filter cartridge 16 is rotated in the clockwise direction indicatedby the arrow in FIG. 6. The bolts 48 are received within the lockingchannels 64 at the locking areas 68 when the rotation is complete. Withspecific reference to FIG. 7, each bolt 48 contacts the upper surface ofits corresponding locking area 68 and the filter is suspended therefrom.

Likewise, with reference to FIG. 4, the filter cartridge 16 may bebottom loaded when the adaptor plate 34 is secured to the tubesheet 20on the lower plenum side of the tubesheet 20. Specifically, the top endcap 52 is placed in proximity with the adaptor plate 34 and the heads ofthe bolts 48 are aligned with the longitudinal channels 62 of theconnection areas 58. Finally, the filter cartridge 16 is inserted withinthe connection areas and rotated so that the bolts 48 are positionedwithin the locking areas 68. At this point, an annular gasket 69contacts the tubesheet 20 to form a seal.

As shown in FIG. 10, a tool 84 may be used to facilitate rotation of thefilter cartridge 16 to and from the locked position of FIG. 7. Tool 84includes a handle 86, a shaft 88 and a cartridge engagement assembly 90.The handle 86 and shaft 88 are preferably made from a square tube ofmetal such as steel and are welded together. The cartridge engagementassembly 90 includes a disc 92 and a rod 94. The disc 92 is preferablywelded to the end of the shaft 88 opposite handle 86. The rod 94 iswelded to either side of the shaft 88 and to the upper surface of disc92. The disc 92 is sized to fit onto the ledge 70. As shown by thephantom lines in FIG. 8, the rod 94 is received within notches 76 and 78when the disc 92 is properly seated. The user merely grasps the handle86 and rotates the tool 84 to rotate the cartridge relative to thetubesheet 20.

With reference to FIG. 9, the potting material 96 of the bottom end cap54 is recessed to present a ledge 95. A pair of upstanding members 98and 100, similar to upstanding members 80 and 82 of the top end cap 52,are located on the ledge 95 and define notches 104 and 106,respectively. A circular depression 102 is formed centrally on thebottom end cap 54. In order to bottom load (or unload) the filtercartridges 16 from the tubesheet 20, the disc 92 is placed withindepression 102 and the rod 94 within the notches 104 and 106 prior torotation of the filter cartridge 16. Typically, the space between thebottom end cap 54 and housing 12 is limited and a tool 84 having arelatively short shaft 88 is desired.

While one embodiment of the filter cartridge 16 consists of thelongitudinal channel 62 and the locking channel 64, the connection areasmay take on any of a number of configurations allowing for top andbottom loading. For instance, a pair of channels may originate fromupper edge 60 and lower edge 61 and be formed angularly with respect toone another. The top end cap 52 could be threaded onto the tube sheet ateither of the two channels and locked at the intersection of thechannels.

With reference to FIGS. 11 and 12, an alternative structure forconnecting a filter cartridge 16 to a tubesheet 20 is illustrated. Acollar 110 extends downwardly from tubesheet 20 into the lower plenum 22of the baghouse 10. Each collar 110 is preferably formed from the samematerial as the tubesheet 20 and is welded thereto. A plurality of bolts112 corresponding to the number of connection areas 58 of the filtercartridge 16 are threaded within apertures 114 located around the collar110. A resilient gasket 116 in the shape of a ring is adhered to theunderside of the planar portion of the tubesheet 108 around the opening26 of the tube sheet. To bottom load the filter cartridge 16, the topend cap 52 is placed within the collar 110 so that bolts 112 arereceived within the longitudinal channels 62. Once the end cap 52contacts resilient gasket 116, the filter cartridge 16 is rotatedrelative to the collar 110 similarly to the rotation with respect to theadaptor plate 34 (described above). The gasket 116 forms a generallyair-tight seal between the filter cartridge 16 and tubesheet 20.

With reference to FIG. 13, a collar 120, which is a variation of collar110, is shown. A plurality of bolts 122 corresponding to the number ofconnection areas 58 that are threaded within apertures 124 are formedwithin the collar 120. However, a small annular ledge 126 is locatedabout the terminal edge of collar 120. A resilient gasket 128 is locatedon the upper surface of ledge 126. The tubesheet 20, having collar 120thereon, is used for top loading the filter cartridge 16. Specifically,the bottom end cap 54 and tubular filter media 56 are placed downwardlyinto the lower plenum 22 through the collar 120. When the top end cap 52is in proximity with the bolts 122, the bolts 122 are aligned relativeto the longitudinal channels 62 and the top end cap 52 is slid into aresting position on small ledge 126. The filter cartridge 16 is rotatedso that the bolts 122 are moved to the locked position, the filtercartridge 16 is lifted slightly from small ledge 126. The resilientgasket 128 forms a generally air-tight seal between the filter cartridge16 and tubesheet 118.

FIG. 14 illustrates a tubesheet 130 for use in conjunction with analternative air filter cartridge shown in FIGS. 15-18. Tubesheet 130includes a plurality of openings 132. Around the periphery of opening132, a plurality of tabs 134 extend inwardly toward the center of eachopening. With reference to FIG. 15, the tabs 134 have a beveled edge 136on a first side of each tab 134, and a body 138 having a width generallyequal to the planar portion of the tubesheet 130. The tabs 136 arepreferably spaced angularly equidistant from one another. Accordingly,the three tabs 134 of the preferred embodiment are offset by 120° fromeach adjacent tab 134. Alternatively, the tubesheet 130 may have varyingnumbers of tabs.

With reference to FIGS. 15-18, an alternative filter cartridge isdesignated generally by the numeral 140. The filter cartridge 140 issimilar to filter cartridge 16 except for the construction of the topend cap 142 formed about a first end of the tubular filter media 144.With specific reference to FIG. 15, the top end cap 142 includes a firstconnector portion 146, a second connector portion 148 and an annularflange 150 disposed therebetween.

With reference to FIGS. 15 and 18, the first connector portion 146 has afirst outer sidewall portion 152, a first inner sidewall portion 154 anda top edge 156. A plurality of recessed channels 158 defining threadsare formed within first outer sidewall portion 152 of first connectorportion 146. A plurality of channel openings 160 extends longitudinallyfrom the top edge 156 of the first connector portion 146 and eachchannel opening 160 is in communication with a corresponding recessedchannel 158. The recessed channels 158 are defined by the upper surface161 of annular flange 150, an end wall 162, and an edge wall 164. Theedge wall 164 has a first portion 166, extending from end wall 162, thatis parallel with the upper surface 161 of annular flange 150 and asecond portion 168 extending between first portion 166 and opening 160that tapers away from the upper surface 161 of flange 150. In thepreferred embodiment, a ridge 170 is defined at the intersection offirst portion 166 and second portion 168. The depth within the outersidewall 152 of each recessed channel 158 is slightly greater than thelength that each tab 134 extends inwardly from the corresponding opening132 of the tubesheet 130.

The annular flange 150 has an outer diameter greater than the diameterof opening 132. A first annular gasket 172 is located on the surface offlange 150 directed toward the first connector portion 146, and a secondannular gasket 174 is located on the surface of flange 150 directedtoward the second connector portion 148. The gaskets 172 and 174 arepreferably made from a resilient material that may be adhered orotherwise secured to the annular flange 150. With specific reference toFIG. 18, the annular flange 150 has an inner diameter and presents aledge 176 around the opening of top end cap 142. A groove 177 is formednear a midpoint of ledge 176. Two pairs of upstanding members 178 and180 are located on the ledge 176 to define opposing notches 182 and 184.The ledge 176 and notches 182 and 184 are used in conjunction with thetool 84 (FIG. 10) as described above.

With reference back to FIG. 15, the second connector portion 148 isgenerally similar to the first connector portion 146. Namely, secondconnector portion 148 has a second outer sidewall portion 186 and abottom edge 188. The inner portion of the second connector portion isformed about the tubular filter media 144 as is known to those ofordinary skill in the art. A plurality of recessed channels 190, eachchannel defining a thread are formed within second outer sidewallportion 186 of second connector portion 148. A plurality of openings 192extend longitudinally from the bottom edge 188 into communication witheach recessed channel 190. Recessed channels 190 are defined by a lowersurface 194 of annular flange 150, an end wall 196, and an edge wall198. The edge wall 198 has a first portion 200 extending from the endwall 196 and disposed parallel with the lower surface 194. A secondportion 202 extends between first portion 200 and opening 192 and tapersaway from flange 150. In the preferred embodiment, a ridge 204 isdefined at the intersection of first portion 200 and second portion 202.Additionally, the second connector portion 148 includes a tapered skirt206 extending from the outer sidewall section 186 and around the tubularfilter media 144. The depth of each recessed channel 190 is the same asthe depth of the recessed channels 158 of the first connector portion.

With reference to FIG. 15, to bottom load the filter cartridge 140 tothe tubesheet 130, the openings 160 are placed in alignment which eachof the tabs 134. When the tabs are placed within openings 160 and are inclose proximity with the upper surface 161 of annular flange 150, thefilter cartridge 140 is rotated in the direction indicated by the arrowin FIG. 16 so that the beveled edge 136 moves within the recessedchannel 158 between annular flange 150 and the second portion 168 ofedge wall 164. As the filter cartridge 140 is further rotated, each tab134 slides between the second portion 168 of edge wall 164 and theannular flange 150. When the rotation is complete, each tab 134 isseated between an end wall 162 and the small ridge 170 at theintersection of first portion 166 and second portion 168 of edge wall164. In this position, the first annular gasket 172 is in connectionwith the bottom of tubesheet 130 to form a seal therebetween. The bottomof filter cartridge 140 may be similar to the bottom end cap of filtercartridge 160 as shown in FIG. 9. Thus, the tool 84 (FIG. 10) may beused to either secure or remove the filter cartridge 140 from thetubesheet 130 when bottom loading (or unloading).

With reference to FIG. 17, the filter cartridge 140 may be top loadedwithin the baghouse 10 use of second connector portion 148.Specifically, the tubular filter media 144 of filter cartridge 140 isplaced through one of the openings 132 of tubesheet 130. When the topend cap 142 is in proximity with the tubesheet 130, the tabs 134 arealigned with the channel openings 192 of second connector portion 148.The tabs are received within the openings 192 so that the tabs are incommunication with the bottom lower surface 194 of annular flange 150.At this point, the filter cartridge 140 is rotated in the directionindicated by the arrow in FIG. 17 so that the tab is positioned withinthe portion of the recessed channel 190 between the edge wall 198 andthe lower surface 194 of annular flange 150. As indicated in phantomlines in FIG. 17, when rotation of the filter cartridge 140 is complete,each tab 134 is positioned between the first portion 200 of edge wall198 and the lower surface 194 of annular flange 150 between the end wall196 and the ridge 204. When the filter cartridge 140 is in the toploaded position, the second annular gasket 174 is in communication withthe upper surface of tubesheet 130 to form a seal therebetween. Tofacilitate the unloading and loading of the filter cartridges 140 fromthe upper plenum 24, the tool 84 (FIG. 10) may be placed on ledge 176and the rod 94 placed within notches 182 and 184.

FIG. 19 demonstrates an alternative embodiment of the filter cartridge140 wherein the channel openings 192 are significantly larger than thechannel openings 160 to facilitate the receipt of larger tabs locatedabout the openings 132 of the tubesheet 130. This is merely illustrativeof one of a number of variations of the inventive construction describedabove.

From the foregoing it will be seen that this invention is one welladapted to attain all ends and objects hereinabove set forth togetherwith the other advantages which are obvious and which are inherent tothe structure. It will be understood that certain features andsubcombinations are of utility and may be employed without reference toother features and subcombinations. This is contemplated by and iswithin the scope of the claims.

Since many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative of applications of the principles of thisinvention, and not in a limiting sense.

What is claimed is:
 1. A filter for use in a baghouse, said baghouse divided into top and bottom plenums by a tubesheet, said tubesheet having a plurality of openings therein, said filter for attachment to said tubesheet at one of said openings, said filter comprising: a filter media; and an end cap having first and second connector portions, wherein said first connector portion mates with the tubesheet at one of the openings when said filter is installed from the bottom plenum, wherein said second connector portion mates with the tubesheet at one of the openings when said filter is installed from the top plenum, and wherein each said connector portion comprises at least one thread.
 2. The filter of claim 1, wherein each said connector portion comprises a plurality of threads.
 3. The filter of claim 2, wherein said connector portions are divided by an annular flange.
 4. The filter of claim 3, wherein said end cap has a first side wall portion at a first side of said annular flange and a second side wall portion at a second side of said annular flange, wherein said threads of said first connector are located in said first side wall portion and said threads of said second connector are located in said second side wall portion.
 5. The filter of claim 4, wherein each said thread comprises a channel.
 6. The filter of claim 5, wherein each said channel is defined by an edge wall, an end wall, and said annular flange.
 7. The filter of claim 6, wherein at least a portion of said edge wall is tapered relative to said annular flange.
 8. The filter of claim 7, wherein a portion of said edge wall is parallel to said annular flange.
 9. The filter of claim 8, wherein a portion of each said channel defined by said tapered edge wall portion and said annular flange communicates with an opening to an edge of said end cap.
 10. The filter of claim 9, wherein said tapered portion transitions to said portion of said edge wall parallel to said flange, and a ridge is located at the intersection of said tapered portion and said portion of said edge wall parallel to said flange.
 11. The filter of claim 10, in combination with said baghouse, wherein each said opening is defined by a periphery having a plurality of tabs extending inwardly toward the center of the opening, wherein each said tab is received within a corresponding one of said threads such that each said tab is positioned against the end wall of said corresponding threads, and wherein said filter is at least partially restrained from rotation in a direction opposite the direction of installation by said ridge.
 12. A filter for use in a baghouse, said baghouse divided into top and bottom plenums by a tubesheet, said tubesheet having a plurality of openings therein, said filter for attachment to said tubesheet at one of said openings, said filter comprising: a filter media; an end cap having first and second connector portions, wherein said first connector portion mates with the tubesheet at one of the openings when said filter is installed from the bottom plenum, and wherein said second connector portion mates with the tubesheet at one of the openings when said filter is installed from the top plenum; annular flange dividing said first connector portion and said second connector portion, said annular flange having a first face and a second face; a first gasket positioned on said first face of said annular flange; and a second gasket positioned on said second face of said annular flange, wherein said first face of said annular flange is sealingly engaged with a bottom of said tubesheet when said filter is installed on said tubesheet from the bottom of said tubesheet, and wherein said second face of said annular flange is sealingly engaged with the top of said tubesheet when said filter is installed on said tubesheet from the top of said tubesheet.
 13. The filter of claim 1, wherein said end cap has a lower portion that depends downwardly and inwardly, whereby said downwardly and inwardly depending portion of said end cap guides the filter through one of said openings when said filter is installed on said tubesheet from a top of said tubesheet.
 14. The filter of claim 1, said end cap having a pair of notches for receiving a tool used to install and remove said filter. 